Process of preparing absorptive carbon



- especially the cheap and very soluble Patented Nov. '19, 1929 STATES ARTHUR BAY, OF FLUSHING, NEW YORK, ASSIGNOR TO CARBIDE AND CHEMICALS CORPORATION, A CORPORATION 01' NEW YORK- PROCESS OF PlBEIABING- ABSORPTIVE CARBON No Drawing.

This invention relates to a process for preparing rigid, coherent masses of hi hly absorbent carbonaceous material in which fragmentary carbonaceous material is first formed into shaped bodies and then activated, without disintegration into fragmentary form.

A preferred method of formin the absorbe'nt mass is first to mix the ragments of absorbent material with a substance capable of giving a coherent and adherent carbonaceous residue on decomposition, and then to decompose the substance so that its carbonaceous residue will firmly bind together the absorbent fragments. These fragments may be ordinary charcoal, but where a high degree of absorptive power is desired, activated carbon should be used. It is known that most organic substances leave a carbonaceous residue on thermal decomposition, and any one of a number of such substances may be used to produce the bonding carbon. To secure a proper distribution of the bonding agent, it is desirable that the carbonaceous material should be in liquid state at some time before it is fully decomposed. This is accomlished by using a solution, or by using a fhsible decomposable substance. Of course, a fusible substance in solution may be used.

As organic compounds for producing the bonding carbon, carbohydrates have many advantages. These substances usually fuse before or during thermal decomposition and are generally quite soluble in water. Sugars, sugars, are satisfactory carbohydrates.

When charcoal is used as the fragmentary material, any grade of reasonable porosity may be selected and bonded with a carbonaceous material of the type above indicated.

For uses in which a high degree of coherence and mechanical strength are required,

the absorptive fragmentary material may be molded under pressure. One use of this kind is in the prepirration of porous masses for use in the tration and purification of li uids.

e following process for preparing blocks of absorptive carbon for water filtering or the like is given byway of illustration: Absorptive carbon, preferably activated carbon ing regulated Application filed October as, 1921. Serial 1%. 511,170.

of fairly high porosity, is pulverized to pass a 35 mesh screen and stay on a 100 mesh screen. The pulverized material is mixed thoroughly with 2 to 3 parts by weight of commercial glucose and 1s molded, under a pressure of about 10,000 lbs. per square inch, into blocks of suitable size. The molded blocks are subjected to heat, which is preferably regulated so as to rise at the rate of about 40 C. per hour to 450500 (l, and the blocks are baked at this final tem erature for about six hours. The resulting lock of bonded activated carbon is strong and has a relatively high absorptive and adsorptive capacity. The pressure may be varied widely according to the particular degree of hardness and strength required in the molded bodies.

Accordmg to a modification of the process heretofore described, charcoal of relatively low absorptive capacity is bonded into a coherent mass and then activated without disintegration. Charcoal in fragmentary form, for example, may be agglomerated with a carbonaceous binder and subjected to the" action of steam for about ahalf hour at a temperature of 7 00-900 C. The absorptive capacity of the charcoal is materially increased by this treatment without substancarbon on thermal decomposition, molding the resulting mixture under pressure, applyheat todecompose said substance, and treating the coherent body thus' formed with a gaseous oxidizing agent to increase its absorptive capacity.

A process of forming strongly coherent eav m of activated carbon which comprises associating such carbon with a carbon-yielding substance, molding the resulting mlxture under pressure, raising the temperature by successive sta es to a point above that at which said car on-yielding substance decomposes, and treating the coherent body thus ormed with a gaseous oxidizing agent to increase its absorptive capacity.

bonaceous bodies which com fragmentary regular shape, hot oxidizing gas to increase its absorptivity. In testimony whereof I aflix msi ature.

a AtTHUR AY.

rises bonding 3. A method of forming absorptive carcharcoal to pro uce a block of" and treating said block with a 

